Abstract
The gradual transformation of heritable quantitative traits due to selection and mutation is a major topic in evolutionary biology. Here, we use a quantitative genetics approach to investigate the coevolution of multiple traits under selection, mutation, and limited dispersal. We track the dynamics of trait means and variance-covariances between pleiotropic traits that experience frequency-dependent selection. Assuming a multivariate-Normal trait distribution, we recover classical dynamics of quantitative genetics, as well as stability and evolutionary branching conditions of invasion analyses, except that due to limited dispersal, selection depends on indirect fitness effects and relatedness. Correlational selection on associations between traits within-individuals depends on the fitness effects of such associations between-individuals. These kin selection effects can be as relevant as pleiotropy for the evolutionary build-up of trait associations. We illustrate this with an example on the coevolution of two social traits whose association within-individual is costly but synergistically beneficial between-individuals. As dispersal becomes limited, associations between-traits between-individuals become increasingly important for correlational selection. Consequently, the trait distribution goes from being bimodal with a negative correlation under panmixia to unimodal with a positive correlation under limited dispersal. More broadly, our approach can help understand the evolution of intra-specific variation in social behaviour.
- Posted August 16, 2018.
